Gun for preparing rapid-hardening coating compositions



Jan. 7, 1964 s. H. REITER 1 GUN FOR PREPARING RAPID-HARDENING COATING COMPOSITIONS Filed Aug. 24, 1962 Jars-.1-

052-1904 Ii 4', 5'9854; @193 fro/rm United States Patent 3,116,878 GUN FGR PREPARING RAPE-HARDENING COATHQG COMPOSITIONS Sydney H. Reiter, 335 Longview Drive, Mountainside, NJ. Filed Aug. 24, 1962, Ser. No. 219,301 7 Claims. (Cl. 239142) This invention relates to a gun for preparing rapidhardening coating compositions, and specifically to a spray gun for admixing rapid-hardening coating compositions and for applying such compositions immediately thereafter to a surface to be coated.

This application is a continuation-in-part of my copending application Serial No. 130,320 filed August 9,

1961, and now abandoned.

Coating compositions which require activation by one or more materials, e.g., catalysts, activators, hardeners or the like to facilitate rapid-hardening of the coatings, are useful in many diverse fields. Rapid and thorough mixing of such activated compositions is necessary immediately prior to the application thereof to surfaces to be coated. If the mixing is not carried out immediately prior to applying such a coating, it is not uniform in texture and composition.

The mixing and application of the rapid-hardening coating compositions has been achieved employing spray guns having mixing chambers and suitable nozzles through which the mixed material may be uniformly deposited upon the selected areas of the surface to be coated. Known spray guns are, however, frequently subject to failure due to clogging of the mixing apparatus by the rapid-hardening coating compositions employed, which tend to interfere with rotating mixer devices and produce overheating of drive motors and eventual failure.

It is among the objects of the present invention to provide a gun for preparing and applying rapid-hardening coating compositions, in which mixing of the compositions is rapidly, completely and efliciently achieved without interference by such compositions with the rotating mixer mechanism of the gun.

A further object of the invention is to provide such a gun which is simple in construction, durable, relatively inexpensive, easy to maintain and readily used by even the most unskilled operator.

Other objects and advantages of the invention will be apparent from the following detailed description thereof.

In accordance with my discovery, a spray gun for mixing and thereafter applying rapid-hardening coating compositions is provided, including a housing having a mixing chamber and a discharge passage connected thereto, inlets through which components of the rapidhardening composition are introduced into the mixing chamber and an agitator mechanism for mixing the components within such chamber. The agitator mechanism comprises a motor or similar drive mechanism mounted adjacent the mixing chamber, a fluid-tight fitting positioned between the mixing chamber and the motor, a hollow flexible tube mounted within the mixing chamber rigidly secured adjacent one end thereof, within the fitting, and a rotor driven by the motor and extending through the flexible tube within at least a portion of the mixing chamber, the rotor being bent in order that rotation thereof by the motor drive produces an agitating movement of the flexible tube within the mixing chamber.

The gun thus provided effects uniform mixing of the components of the coating composition by the gyrating movement of the flexible tube within the mixing chamber. Since the flexible tube is rigidly mounted within a fluidtight fitting sealing the mixing chamber, its gyration or twisting movement is produced by the rotor member 3,ll6 ,8?8 Patented Jan. 7, 1964 2 enclosed therein without entailing contact between the rapid-hardening materials mixed and any rotating parts. Hence, all possibility of the coating composition clogging the mixing mechanism and of possible failure of the spray gun is avoided.

As will appear from the following description of a preferred embodiment of the invention, the gun may be readily and speedily disassembled and cleaned. Moreover, the device is so constructed that each of the parts is instantly removable and replaceable as when it is desired, for example, to change a feed or discharge nozzle to vary the flow of the composition fed through the gun.

For a fuller understanding of the nature and objects of the present invention, reference is made to the following detailed description of a preferred spray gun taken in connection with the accompanying drawing, in which:

FIGURE 1 is a longitudinal vertical section through the gun;

FIGURE 2 is a partial elevation of the gun showing the spray nozzle and the bracket structure facilitating ready disassembly of the nozzle structure from the gun; and

FIGURE 3 is an end view in the direction of the line 33 in FIGURE 1, showing the discharge end of the gun housing.

Referring now to the drawing, the spray gun illustrated includes a housing 11 having an axial bore 12 extending longitudinally thereof. A drive motor 13 is mounted Within the housing 11 removably secured to a mounting sleeve 14, as by set screws 15. The motor 13 may be of any conventional type, the known compressed air actuated motors having been found particularly suitable for use in the present invention.

The bore 12 within the housing 11 defines a generally cylindrical mixing chamber 16 and an adjacent enlarged chamber 17 sealed from the mixing chamber by a fluidtight fitting 18. The drive motor 13 is connected to an agitator mechanism in the mixing chamber through the fitting 18. Secured to the shaft of motor 13, as by a collar 19, is a thin rod 21. The rod 21 is received within a hollow flexible tube 22, which is rigidly mounted within the fitting 18. The periphery of the tube 22 secured within the fitting 18 defines a pressure-tight seal preventing materials introduced into the mixing chamber 16 from con tacting the rotatable rod 21 and its associated drive mechanism.

The rod 21 and the flexible tube 22 extend longitudinally of the mixing chamber 16 to a point adjacent the chamber end opposite the fitting 18. The end of the flexible tube 22 within the mixing chamber is sealed at 23, thereby completely sealing the rotatable rod 21 from the mixing chamber.

The rod 21 is slightly bent at a point 24 intermediate its ends, as shown in FIGURE 1. Due to this configuration, rotation of the rod 21 within the flexible tube 22 causes the tube to gyrate or rotate eccentrically of the mixing chamber 16, to thereby eflect mixing of the coating composition fed thereto.

The mixing chamber 16 has one or more intake or inlet ports through which the coating composition is introduced. It will be understood that if a single inlet port is utilized, each of the components of the composition, e.g., polymeric materials, catalysts, and/0r accelerators, is introduced through such a port. It is preferred, however, to employ two inlet ports 25 and 26, connected to supply conduits 27 and 28, respectively, through which the coating composition components are separately fed, whereby to effect mixing of the composition entirely within the mixing chamber 16 to promote uniformity in the texture and composition of the coating material fed from the spray gun. While in the preferred form of the invention a pair of inlet ports are thus utilized it will be 3 understood that, depending upon the nature of the coating composition components, any number of inlet ports and supply conduits may be utilized, as desired. It is, for example possible to provide a gun with a separate inlet port for a cleaning or flushing agent by means of which residual materials may be flushed from the gun.

A discharge or outlet end assembly 29 is removably secured to the main portion of the housing 11 in which the mixing chamber 16 is formed, as by a thumb screw 31. Simple removal of the thumb screw facilitates disassembly of the spray gun for cleaning or replacement of the mixing chamber or discharge elements.

A shortdischarge passage 32 is formed in the end assembly '29 longitudinally of the mixing chamber 16. Adjacent the discharge passage 32 a core piece 33 of generally conical shape is disposed to prevent unmixed materials fed through inlets and 26 into the mixing chamber 16, from passing directly through the passage 32 without prior mixing by the agitator mechanism. As shown in FIGURE 1, the core piece 33 extends into the mixing chamber and provides a centrally tapered deflector element about which the fiexibletube 22 containing the agitator rod 21 rotates eccentrically, to thereby produce thorough mixing of the coating composition components.

Outlet passage 32 is connected to an intersecting generally vertical discharge passage 34 formed within the end assembly 29. The top 35 of the discharge passage 34 extends slightly above the outlet passage 32 and receives an O-ring 36 held therein by a retainer or washer 37 having a diameter sufficient to be received inmating relation with an adjacent discharge tube, described hereinafter.

The discharge tube, indicated generally at 38, is slidably positioned within the discharge passage 34 of the gun housing. As shown in FIGURE 2, the discharge tube may be connected at its extremity with a nozzle 39 for dispensing the admixed coating composition. Any suitable nozzle can be thus utilized, such as the type having a linear aperture for producing a fan-like spray of the coating mixture. Alternatively, the discharge tube may be closed at its lower end and provided with a plurality of discharge orifices for dispensing the coating mixture directly therefrom. The latter construction, in which the discharge tube serves as a nozzle itself, is disclosed in the aforesaid copending application Serial No. 130,320. When the spray gun is employed to apply materials for casting purposes or for laying down heavy material deposits, the lower end of the discharge tube may, if desired, be left open without the use of any discharge nozzle, the gun thereby discharging the materials in a single stream.

The upper end of the discharge tube 38 is provided with an internal shoulder 42 which defines a seat dimensioned to engage the washer 37 and the O-ring 36, as shown in FIGURE 1, to thereby seal the discharge tube from the mixing chamber 16. An annular internal seat is also provided in the discharge passage 34 having a ring 41 positioned therein permitting the discharge tube 38 to slide axially of the discharge passage, but blocking the passage of the coating composition between the walls of the discharge tube and the discharge passage.

Frictionally engaging the discharge tube 38 is an external retaining ring 43, which is normally urged upward by a compression spring 44 hearing thereon. In order to prevent displacement of the retaining ring axially of the discharge'tube an annular channel or groove may be formed in the surface of the discharge tube to define a seat for the retaining ring. The discharge tube is thus normally urged into seating and sealing engagement with the O-ring 36.

A trigger 45 is pivotally mounted beneath the housing 11, as by a screw 46. The trigger 45 may be pivoted manually, as by finger pressure. The leading portion of the trigger is bifurcated at 47 and is engaged between the lower wall of the end assembly 29 of the housing and the retaining ring 43 mounted on the discharge tube 38. Upon applying pressure to the trigger 45, the leading portion 47 engages the retaining ring 43 and moves it in a generally downward direction against the pressure of the spring 44. Since the retaining ring is mounted on the discharge tube 38, the tube is simultaneously pushed downward, unseating the shoulder 42 thereof from the O-ring 36 to facilitate feeding material under pressure from the mixing chamber 16 through the discharge tube and out of the spray gun.

The discharge tube and nozzle assembly is removably secured to the housing 11 by a U-shaped bracket 48 (FIGURES 2 and 3) mounted on the end assembly 29 of the gun housing. The bracket base 49 embraces the discharge tube 38 and serves as a seat for the compres-- sion spring 44.

The bracket 48 is conveniently mounted on the gum housing by the provision of grooves 51 extending obliquely of its sides adapted to receive mating pins 52 formed integrally with the housing; hence the bracket and the; discharge tube held thereby are readily removable by simply sliding the bracket obliquely to disengage the grooves 51 and the pins 52. When it is desired to replace a discharge tube With'another such tube, either because of clogging or because of the desire to employ a difierent discharge tube, e.g., one having a different nozzle secured thereto or one such as that disclosed in the aforesaid copending application, it is only necessary to remove the bracket 48 and replace the tube.

The operation of the spray gun of this invention is initiated by attaching supply lines to the couplings at the lower ends of conduits 27 and 28 and introducing the components of the rapid-hardening composition under pressure to such supply lines. Upon energizing the motor 13, the agitator rod 21 rotates, thereby effecting gyration of the flexible tube 22 within the mixing chamber 16 and producing thorough mixing of the components fed through the inlets 25 and 26. The trigger 45 may then be pivoted to unseat the discharge tube 38 from the O-ring 36, whereby a continuous flow of the coating composition is fed under pressure through the outlet passage 32 into the discharge tube 38 from thehermetically sealed mixing chamber 16. The rapidly rotating agitator mechanism comprising the flexible tube 22 and the rotating rod element 21 contained therein produces a homogeneous mixture of the coating composition which flows through the discharge tube and is sprayed through the nozzle 39 to the surface to be coated.

It is convenient for the user to operate the gun by grasping the inlet conduits 27 and 28 with the palm of his hand and engaging the trigger 45 with his fingers. It

' Will be understood, however, that the fittings 27 and 28 maybe covered with a suitable pistol type grip to facilitate actuating the spray gun. Upon release of the trigger 45, the compression spring 44 restores the discharge tube 33 into sealing engagement with the O-ring 36 at the top of the discharge passage 34, thereby terminating the coating operation until the trigger is again actuated.

The gun made in accordance with this invention provides a homogeneous mixture of any rapid-hardening coating composition which may be carefully controlled as to flow, continuity and direction. Moreover, operation of the gun does not entail possible interference by the components of the coating composition with any rotating mixer parts and thereby avoids possible failure of the mixing device. Additionally, the construction of the gun facilitates simple and rapid disassembly of its component elements for cleaning or replacement thereof.

It will be understood that certain changes may be made in the structure of the present device without depart ing from the scope of this invention. Hence, when high discharge pressures or extremely rapid reacting materials are employed, alternative means may be provided for flushing the contents of the mixing chamber with a solvent liquid and/or for controlling the fluid discharge from the inlet conduits leading to the mixing chamber. Accordingly, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A gun for preparing and applying rapid-hardening coating compositions, comprising a housing with a mixing chamber and a connected discharge passage, means for introducing components of a rapid-hardening coating composition into the mixing chamber and an agitator mechanism for mixing the components Within the chamber, the agitator mechanism including:

a drive means mounted adjacent the mixing chamber,

a fluid-tight fitting disposed intermediate the mixing chamber and the drive means,

a hollow flexible tube mounted within the mixing chamber one end of which is closed and is positioned Within the mixing chamber and the other end of which makes a fluid tight seal with the fitting, and

a rotor element rotatably engaged with the drive means and received within the flexible tube, extending into at least a portion of the mixing chamber, the rotor element being bent in order that rotation thereof by the drive means produces an agitating movement of the flexible tube Within the mixing chamber.

2. The gun as defined in claim 1, wherein said other end of the flexible tube extends through the fitting to a point outside of the mixing chamber, and the rotor element is a thin bent rod member rotatably mounted with respect to the flexible tube.

3. The gun as defined in claim 1, in which a deflector member is disposed Within the mixing chamber adjacent the discharge passage connected thereto, for deflecting the composition components introduced into the mixing chamber into the path of the agitator mechanism and thereby preventing unmixed materials from passing directly into the discharge passage of the gun.

4. The gun as defined in claim 1, including a discharge tube having an open end slidably mounted within said discharge passage, means for sealing the open end of the discharge tube against the entry of the coating composition components, means normally urging the discharge tube into seating engagement with the sealing means, and means to unseat the discharge tube from the sealing means to thereby facilitate the passage of the mixed coating composition components through the discharge tube out of the gun.

5. A gun for preparing and applying rapid-hardening coating compositions, comprising:

(a) a housing with a mixing chamber and a connected discharge passage;

(b) means for introducing components of a rapidhardening coating composition into the chamber;

(0) an agitator mechanism for mixing the components within the mixing chamber, the agitator mechanism including:

(1) a drive motor mounted Within the housing adjacent the mixing chamber,

(2) a fluid-tight fitting disposed intermediate the mixing chamber and the drive motor,

(3) a hollow flexible tube extending through the mixing chamber having one end closed and mounted within the chamber and rigidly secured adjacent the other end thereof within the fitting and forming a fluid-tight seal therewith, and

(4) a thin bent rod rotor member rotatably driven by the drive motor and extending from the drive motor through the fluid-tight fitting and flexible tube lengthwise of the mixing chamber, the rotor member being bent at a point intermediate its length in order that rotation thereof by the drive motor effects gyratory movement of the flexible tube within the mixing chamber; and

(d) an elongated discharge tube having one end slidably mounted within the discharge passage, and through which tube the admixed coating composition components are discharged from the gun.

6. The gun as defined in claim 5, including:

a seat in the discharge passage defining a closure for sealing the open end of the discharge tube against the entry of material,

a trigger pivotally attached to the housing;

a shoulder on the discharge tube engageable by the trigger to unseat the discharge tube; and

a spring engaging the discharge tube and normally urging it into sealing engagement with the seat.

7. The gun as defined in claim 5 including a bracket removably securing said discharge tube to said housing, said bracket having a pair of elongated grooves receiving a corresponding pair of pins formed integrally With said housing.

References Cited in the file of this patent UNITED STATES PATENTS 2,485,854 Zona Oct. 25, 1949 2,705,132 Neville Mar. 29, 1955 2,764,565 Hoppe et al Sept. 25, 1956 2,788,337 Preiswerk et a1 Apr. 9, 1957 2,857,202 Snyder Oct. 21, 1958 2,970,773 Keryluk et al Feb. 7, 1961 

1. A GUN FOR PREPARING AND APPLYING RAPID-HARDENING COATING COMPOSITIONS, COMPRISING A HOUSING WITH A MIXING CHAMBER AND A CONNECTED DISCHARGE PASSAGE, MEANS FOR INTRODUCING COMPONENTS OF A RAPID-HEARDENING COATING COMPOSITION INTO THE MIXING CHAMBER AND AN AGIATOR, MECHANISM FOR MIXING THE COMPONENTS WITHIN THE CHAMBER, THE AGIATATOR MECHANISM INCLUDING: A DRIVE MEANS MOUNTED ADAJCENT THE MIXING CHAMBER, A FLUID-TIGHT FITTING DISPOSED INTERMEDIATE THE MIXING CHAMBER AND THE DRIVE MEANS, 